Many data storage devices move a sequential information storage medium, such as for example a magnetic tape, across a head module comprising multiple data elements in combination with two or more servo elements. To write and read data to and from the storage medium, it is necessary that the head module be precisely positioned with respect to data tracks encoded in the storage medium. The demand for greater data storage densities has forced a reduction in size of the individual data tracks. Furthermore, the storage medium itself is subject to lateral movement as it is being moved across a head module. Thus, the position of the head module must continuously be adjusted.
Using prior art apparatus and methods, servo elements are used to detect servo bands encoded in a sequential information storage medium. Data elements are used to write data to, and/or read data from, a sequential information storage medium. Such prior art data elements are not capable of reliably detecting servo patterns encoded in a servo band.